Study On The Planning Of The Flood Prevention And Storm Drainage Of The Main Stream Of Xiaohaihe,in The City Of Conghua,Guangdong

This paper is focused on the study of management of flood prevention and storm drainage for the main river of Xiaohaihe. Xiaohaihe, called Qujiang water in the past, is located in the south of Conghua, Guangdong. It is the largest branch of Liuxi river, and flows into Liuxi from south to north in the northwest of South village, Jiangpu town. The flood control project, along the banks of Liuxi river has been proceeding these years and will be finished at the end of 2005. Recently, the embankment located on the mouth of Liuxi river, where Xiaohaihe flows into, has achieved the standard. Aiming at completing the system of flood control for Xiaohaihe river, the flood control projects should be taken into account, thus it is quite necessary to study on the management of those projects.Based on the analysis of flood disasters and present situation of hydraulic engineering works, several practical problems about flood control and storm drainage, including none of water storage controlling works, the low standard of embankment, and the lag of project management etc., were presented in this paper. According to the characteristics of hydrology and weather in this region, storm design, empirical equation method, deducing equation method and synthetical unit hydrograph method are coupled to design flood for regional natural stream. The benefit from the flood prevention of water storage works in this area, namely Nanda reservoir, was computed, based on the design floods and the level of design floods respectively, and several combination means of the initial level of the design flood for calculating were adopted.The detailed measures for the management of regional flood control and the particular scheme of regional storm drainage were put forward in this paper. Meanwhile, the size of the works, management measure, fund and practical implement were all analyzed or budgeted, and appraisal of the environmental effect and economy were also made in this paper. In the management of flood control project, the construction of embankment should be put in the prior position. In order to minimize the investment, the existed embankment should be applied as many as possible, while farmland should be taken as little as possible and local material should be enough utilized. In the scheme of storm drainage, the principle, namely mainly self drainage with the assistant of pumping, should be insisted on. Combining the practical condition of geology to separate regions for storm drainage, arranging the projects that traverse the embankment reasonably, and making sure their form and size, to complete the system of flood control and storm drainage and make it plausible.